Vaadin8 Custom Font Not Working

Vaadin 6 / 7 / 8
1

Hello,

I am using vaadin8. I wrote simple custom font. Here is my code.

public enum MyCustomFont implements FontIcon {
    HOME;

    @Override
    public String getMIMEType() {
        throw new UnsupportedOperationException(
            FontIcon.class.getSimpleName()
            + " should not be used where a MIME type is needed.");
    }

    @Override
    public String getFontFamily() {
        return "sans-serif";
    }

    @Override
    public int getCodepoint() {
        return 0;
    }

    @Override
    public String getHtml() {
        return "<span class=\"v-icon fal fa-home\"></span>";
    }
}

Button buttonTest = new Button("test", MyCustomFont.HOME);

When i am usign this font in button, getHtml() method never calls.
Only getFontFamily() method calls from vaadin. So in getHtmlMethod my fal and fa-home classes magically dissappears and replaced with getFontFamily method results. Please help. How can i ensure that MyCustomFont.getHtml() method will call.

Please Help, Thanks.